How to reproduce:
1. Open the user’s attached “UIToolkitTest.zip” project
2. In the Hierarchy window, select “Test Component” GameObject
3. In the Inspector in the “Test Component” Component, change the places of elements
4. Press the “Add” Button below the elements
5. Observe the result

Expected result: the newly added element has handles
Actual result: the newly added element doesn’t have handles

Reproducible with: 2023.2.14f1, 2023.3.0b10
Could not test with: 2021.3.36f1, 2022.3.21f1 (Errors after project downgrade)

Reproduced on: macOS 14.3.1 (Intel)
Not reproducible on: No other environment tested